Contributors EH participated in the design and coordination of the study, evaluated results, performed statistical analysis and drafted
the manuscript. VL prepared antigens for assessment of antibody presence. JS performed the immunoassays. RT participated in
the design of the study and helped to draft the manuscript. All authors read and approved the final manuscript.

Accepted 9 May 2012

Published Online First 8 June 2012

Abstract

Objectives The assessment of the prevalence of antibodies to human papillomaviruses (HPV) in the healthy population is essential for
effective planning of HPV vaccine implementation into the preventive programmes for HPV-associated diseases and for the prospective
monitoring of the impact of HPV vaccines in the Czech population.

Results The seroprevalences for HPV-6, 11, 16, 18, 31 and 33 were 23.8%, 15.2%, 14.5%, 9.9%, 16.4% and 9.6% in women and 18.4%, 13.7%,
6.5%, 5.4%, 6.1% and 4.3% in men. For both genders, except for HPV11, these rates were age dependent. The prevalence of antibodies
to HPV-16 and/or 18 reached the maximum of 27.0% in women 30–39 years of age and of 14.4% in men 50–59 years of age. The highest
proportion of individuals' seropositive for any of the vaccine types HPV-6/11/16/18 was in 30- to 39-year-old women (50.0%)
and in ≥60-year-old men (37.6%). Antibodies specific for vaccine HPV types were detected in 18.0% of children 6- to 14-year-old
but in 26.4%, those older than 14 years.

Conclusions The data reveal age-specific differences in the HPV seropositivity rates between healthy women and men and support the implementation
of HPV vaccination in the Czech Republic before the age of 13.

Footnotes

Funding The work was funded by the Internal Grant Agency of the Ministry of Health of the Czech Republic, grants Nos. NS/9984 and
NT/12372. The funder provided financial support for this project. The funder had no role in study design, data collection
and analysis, decision to publish or preparation of the manuscript.

Competing interests RT is a member of the Czech GSK advisory board; the other authors have no conflicts of interest.

Patient consent Serum samples were derived from serological surveys performed in the Czech Republic by the National Institute of Public Health
aimed to provide information about the immunity status of the population and basic data for decision on potential changes
in the vaccination strategies. Such surveys have been carried out in the Czech Republic since 1971. Persons enrolled in the
survey were randomly selected in cooperation with regional and district sanitary offices and with practitioners for adults,
adolescents and children. Blood samples were collected in various urban and rural populations from healthy individuals 6–64 years
of age. The blood samples were taken from subjects with no acute febrile disease and no signs of immunodeficiency on the day
of sampling. All enrolled subjects signed informed consent, in case of children, the informed consent was signed by parents.
The blood sample was coded with regard to region, district, physician and client. All sera were aliquoted, registered in the
Serum Bank of the Centre for Epidemiology and Microbiology, National Institute of Public Health, and kept frozen. The set
of samples analysed in our study comprised of sera collected in the year 1996 and 2001. For the purpose of our study, all
sera were marked by laboratory ID and no identification of particular person was possible. In addition, we included sera from
anonymous blood donors sampled in the period of 1999–2005. All blood donors sign information consent form under the blood
sampling. Those samples are mandatory tested for the presence of markers of infections transmitted by blood and discarded.

Ethics approval The study was approved by the Ethics committee of Institute of Hematology and Blood Transfusion (#EK 2IGA/9/2009).